The New upgrated diameter Ø14mm eGo Mini Protank-3 Clearomizer Airflow adjustment Bottom Base unique airflow valve features 4 holes to control the airflow to the amount you prefer. Rotate the Airflow control valve to the most comfortable one for you. You can now adjust how hard or soft the draw is, how warm or cold the vapor is, and how much vapor is produced.You also need protank BDC dual coil head, mini protank-3 tube with tip work together.NOT interchangeable with Mini Protank BCC Clearomizer.